‘Chain-link’ E. coli capsule may deliver vaccines

The thought of ingesting E. coli makes most people recoil but what if a harmless strain of the bacteria could improve vaccines?

Researchers have developed an E. coli-based transport capsule designed to help next-generation vaccines do a more efficient and effective job than today’s immunizations. The research, reported in the journal Science Advances, highlights the capsule’s success in fighting pneumococcal disease, an infection that can result in pneumonia, sepsis, ear infections, and meningitis.

“It’s a bit counterintuitive given what you hear about E. coli, but there are many strains of the bacteria, most of which are perfectly normal in the body, that have great potential to fight disease,” says Blaine A. Pfeifer, associate professor of chemical and biological engineering in the University at Buffalo School of Engineering and Applied Sciences.

Pfeifer is the study’s co-lead author along with his former student Charles H. Jones, who is leading efforts to commercialize the biotechnology as CEO and founder of Buffalo, New York-based startup Abcombi Biosciences.

The core of the transport capsule the team developed is harmless E. coli. Around the bacteria, the researchers wrapped a synthetic polymer—called poly (beta amino ester)—that resembles a chain-link fence. The positive-charged polymer, combined with the negative-charged bacteria cell wall, create a sort of hybrid capsule.

To test the capsule, the researchers then inserted a protein-based vaccine, also being commercialized by Abcombi, designed to fight pneumococcal disease. They tested this work in mice.

The capsule’s hybrid design provided:

Both passive and active targeting of specific immune cells called antigen-presenting cells that trigger an immune response.

It’s also relatively inexpensive to create and flexible in terms of use. For example, the capsule could be used as a delivery device for therapies that target cancer, viral-based infectious disease, and other illnesses.
The National Institutes of Health and the Arthur A. Schomburg Fellowship Program at the University at Buffalo supported the work.